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4349 | Serge | 1 | /* |
2 | * ADX ADPCM codecs |
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3 | * Copyright (c) 2001,2003 BERO |
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4 | * |
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5 | * This file is part of FFmpeg. |
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6 | * |
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7 | * FFmpeg is free software; you can redistribute it and/or |
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8 | * modify it under the terms of the GNU Lesser General Public |
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9 | * License as published by the Free Software Foundation; either |
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10 | * version 2.1 of the License, or (at your option) any later version. |
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11 | * |
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12 | * FFmpeg is distributed in the hope that it will be useful, |
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13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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15 | * Lesser General Public License for more details. |
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16 | * |
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17 | * You should have received a copy of the GNU Lesser General Public |
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18 | * License along with FFmpeg; if not, write to the Free Software |
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19 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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20 | */ |
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21 | |||
22 | #include "avcodec.h" |
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23 | #include "adx.h" |
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24 | #include "bytestream.h" |
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25 | #include "internal.h" |
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26 | #include "put_bits.h" |
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27 | |||
28 | /** |
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29 | * @file |
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30 | * SEGA CRI adx codecs. |
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31 | * |
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32 | * Reference documents: |
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33 | * http://ku-www.ss.titech.ac.jp/~yatsushi/adx.html |
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34 | * adx2wav & wav2adx http://www.geocities.co.jp/Playtown/2004/ |
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35 | */ |
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36 | |||
37 | static void adx_encode(ADXContext *c, uint8_t *adx, const int16_t *wav, |
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38 | ADXChannelState *prev, int channels) |
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39 | { |
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40 | PutBitContext pb; |
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41 | int scale; |
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42 | int i, j; |
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43 | int s0, s1, s2, d; |
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44 | int max = 0; |
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45 | int min = 0; |
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46 | int data[BLOCK_SAMPLES]; |
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47 | |||
48 | s1 = prev->s1; |
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49 | s2 = prev->s2; |
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50 | for (i = 0, j = 0; j < 32; i += channels, j++) { |
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51 | s0 = wav[i]; |
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52 | d = ((s0 << COEFF_BITS) - c->coeff[0] * s1 - c->coeff[1] * s2) >> COEFF_BITS; |
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53 | data[j] = d; |
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54 | if (max < d) |
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55 | max = d; |
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56 | if (min > d) |
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57 | min = d; |
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58 | s2 = s1; |
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59 | s1 = s0; |
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60 | } |
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61 | prev->s1 = s1; |
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62 | prev->s2 = s2; |
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63 | |||
64 | if (max == 0 && min == 0) { |
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65 | memset(adx, 0, BLOCK_SIZE); |
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66 | return; |
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67 | } |
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68 | |||
69 | if (max / 7 > -min / 8) |
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70 | scale = max / 7; |
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71 | else |
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72 | scale = -min / 8; |
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73 | |||
74 | if (scale == 0) |
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75 | scale = 1; |
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76 | |||
77 | AV_WB16(adx, scale); |
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78 | |||
79 | init_put_bits(&pb, adx + 2, 16); |
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80 | for (i = 0; i < BLOCK_SAMPLES; i++) |
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81 | put_sbits(&pb, 4, av_clip(data[i] / scale, -8, 7)); |
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82 | flush_put_bits(&pb); |
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83 | } |
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84 | |||
85 | #define HEADER_SIZE 36 |
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86 | |||
87 | static int adx_encode_header(AVCodecContext *avctx, uint8_t *buf, int bufsize) |
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88 | { |
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89 | ADXContext *c = avctx->priv_data; |
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90 | |||
91 | bytestream_put_be16(&buf, 0x8000); /* header signature */ |
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92 | bytestream_put_be16(&buf, HEADER_SIZE - 4); /* copyright offset */ |
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93 | bytestream_put_byte(&buf, 3); /* encoding */ |
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94 | bytestream_put_byte(&buf, BLOCK_SIZE); /* block size */ |
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95 | bytestream_put_byte(&buf, 4); /* sample size */ |
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96 | bytestream_put_byte(&buf, avctx->channels); /* channels */ |
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97 | bytestream_put_be32(&buf, avctx->sample_rate); /* sample rate */ |
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98 | bytestream_put_be32(&buf, 0); /* total sample count */ |
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99 | bytestream_put_be16(&buf, c->cutoff); /* cutoff frequency */ |
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100 | bytestream_put_byte(&buf, 3); /* version */ |
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101 | bytestream_put_byte(&buf, 0); /* flags */ |
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102 | bytestream_put_be32(&buf, 0); /* unknown */ |
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103 | bytestream_put_be32(&buf, 0); /* loop enabled */ |
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104 | bytestream_put_be16(&buf, 0); /* padding */ |
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105 | bytestream_put_buffer(&buf, "(c)CRI", 6); /* copyright signature */ |
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106 | |||
107 | return HEADER_SIZE; |
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108 | } |
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109 | |||
110 | static av_cold int adx_encode_init(AVCodecContext *avctx) |
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111 | { |
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112 | ADXContext *c = avctx->priv_data; |
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113 | |||
114 | if (avctx->channels > 2) { |
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115 | av_log(avctx, AV_LOG_ERROR, "Invalid number of channels\n"); |
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116 | return AVERROR(EINVAL); |
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117 | } |
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118 | avctx->frame_size = BLOCK_SAMPLES; |
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119 | |||
120 | /* the cutoff can be adjusted, but this seems to work pretty well */ |
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121 | c->cutoff = 500; |
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122 | ff_adx_calculate_coeffs(c->cutoff, avctx->sample_rate, COEFF_BITS, c->coeff); |
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123 | |||
124 | return 0; |
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125 | } |
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126 | |||
127 | static int adx_encode_frame(AVCodecContext *avctx, AVPacket *avpkt, |
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128 | const AVFrame *frame, int *got_packet_ptr) |
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129 | { |
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130 | ADXContext *c = avctx->priv_data; |
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131 | const int16_t *samples = (const int16_t *)frame->data[0]; |
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132 | uint8_t *dst; |
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133 | int ch, out_size, ret; |
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134 | |||
135 | out_size = BLOCK_SIZE * avctx->channels + !c->header_parsed * HEADER_SIZE; |
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136 | if ((ret = ff_alloc_packet2(avctx, avpkt, out_size)) < 0) |
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137 | return ret; |
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138 | dst = avpkt->data; |
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139 | |||
140 | if (!c->header_parsed) { |
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141 | int hdrsize; |
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142 | if ((hdrsize = adx_encode_header(avctx, dst, avpkt->size)) < 0) { |
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143 | av_log(avctx, AV_LOG_ERROR, "output buffer is too small\n"); |
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144 | return AVERROR(EINVAL); |
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145 | } |
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146 | dst += hdrsize; |
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147 | c->header_parsed = 1; |
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148 | } |
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149 | |||
150 | for (ch = 0; ch < avctx->channels; ch++) { |
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151 | adx_encode(c, dst, samples + ch, &c->prev[ch], avctx->channels); |
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152 | dst += BLOCK_SIZE; |
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153 | } |
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154 | |||
155 | *got_packet_ptr = 1; |
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156 | return 0; |
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157 | } |
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158 | |||
159 | AVCodec ff_adpcm_adx_encoder = { |
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160 | .name = "adpcm_adx", |
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161 | .long_name = NULL_IF_CONFIG_SMALL("SEGA CRI ADX ADPCM"), |
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162 | .type = AVMEDIA_TYPE_AUDIO, |
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163 | .id = AV_CODEC_ID_ADPCM_ADX, |
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164 | .priv_data_size = sizeof(ADXContext), |
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165 | .init = adx_encode_init, |
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166 | .encode2 = adx_encode_frame, |
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167 | .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_S16, |
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168 | AV_SAMPLE_FMT_NONE }, |
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169 | };>>>>>><>> |